Contact pin crimping machine



Nov. 16, 1954 J. w. FULTON El'AL CONTACT PIN CRIMPING MACHINE 5 Sheets-Sheet 1 Filed Aug. 22, 1950 lnverft'ors John W. FuL tron, Rober'i' A.Kuebler", by M6 KW Theh" Akkorneg.

Nov. 16, 1954 J. w. FULTON ETAL CONTACT PIN CRIMPING MACHINE 3Sheets-Sheet 2 Filed Aug. 22, 1 950 n 9 a m swww o mu IA M L $2 JO mNov. 16, 1954 J. w. FULTON ETAL CONTACT PIN CRIMPING MACHINE 3SheetsSheet 3 Filed Aug. 22, 1950 Irwvenkom Johnw Fukton. Robefi: A.KuebLer",

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sappy CONTACT PIN CRIMPING MACHINE John W. Fulton, Chardon, and RobertA. Kuebler, Cleveland Heights, Ohio, assignors to General ElectricCompany, a corporation of New York Application August 22, 1950, SerialNo. 180,819

3 Claims. (Cl. 153-1) This invention relates generally to themanufacture of outside terminal connectors for electric dischargedevices such as fluorescent lamps and radio tubes, and more particularlyto an automatic machine for making a solderless contact pin assemblywherein a tubular pin is crimped over a lead wire threaded through itsbore.

In the manufacture of electrical devices requiring an outside connectorfor a lead wire penetrating into the device through a seal, it hasgenerally been the practice to utilize brass pins and to make a solderedjoint between the lead wire and the pin. Although such soldered contactpin connector assemblies are generally satisfactory, they are relativelyexpensive due to the large amount of manual labor involved.

1n the copending United States patent application of Robert A. Kuebler,Serial No. 180,818, filed August 22, 1950, entitled Crimped Contact PinAssembly, and assigned to the same assignee as the present invention,there is disclosed a solderless contact pin and lead wire assemblywherein the pin is crimped by longitudinal tapered indentations onopposite sides. This assembly has the decided advantages that thegeneral outline of the pin is not distorted as a result of the crimpingoperation, the strength of the pin is equal to or superior to that of asoldered pin, and a cheaper material such as aluminum, which is notreadily soldered, may be used for the pin.

The general object of this invention is to provide new and improvedapparatus for making a crimped contact pin to lead wire assembly.

The specific object of the invention is to provide a power actuatedmachine for automatically making the crimped contact pin assembliesdescribed in the abovementioned copending application.

In accordance with the invention, there are provided a pair of movablecompression dies having semicylindrical grooves cut into their adjacentfaces for defining a cylindrical cavity in which the pin is confinedwhen the dies are moved into apposition. Narrow slots are cut into thecompression dies in a direction parallel to their paths of movement andabutting against the semicylindrical grooves. A pair of indentingpunches move through the slots for crimping the pin to the lead wire bymeans of corresponding indentations on opposite sides of the pins. Theconfining dies prevent any distortion of the pin during the crimpingoperation and, in the case of pins formed from sheet metal and having alongitudinal seam, prevent any splitting of the pins along the seam. Inthe preferred form of our invention, the indenting punches have slopingfaces for providing a deeper indentation at the outer end of the pinthan at the inner end and one of the punches is split near its center. Aslope is provided in order to cause a flow of metal in the lead wirefrom the outer to the inner end of the pin, which flow lengthens thelead wire in the direction of the seal thereby preventing breakage ofthe seal. The compression dies and the indenting punches are preferablypower actuated and automatically controlled in a manner to be more fullydescribed hereinafter.

For further objects and advantages and for a better understanding of theinvention, attention is now directed to the following description andaccompanying drawings. The features of the invention believed to benovel will be more particularly pointed out in the appended claims.

.In the drawings, wherein like reference numerals refer to correspondingparts in the different figures:

States Patent 2,694,433 Patented Nov. 16, 1954 Fig. l is a pictorialrepresentation of one end of a fluorescent lamp of a well-knowncommercial type.

Fig. 2 is a pictorial sectionalized view illustrating the essentialfeatures of the compression dies and indenting punches in accordancewith the preferred embodiment of our invention.

Fig. 3 is a pictorial view of an automatic contact pin crimping machineconstituting the preferred embodiment of our invention. Portions of themachine have been cut away, and other portions have been exploded inorder to provide a more readily understood illustration.

Pig. 4 is a simplified representation, partly schematic in form,illustrating the electrical and mechanical control apparatus utilized inconjunction with the machine of Fig. 3, for effecting automaticoperation thereof.

Referring to Fig. 1, there is shown an end of a commercial fluorescentlamp 1 of conventional design, comprising a glass envelope 2 having itsextremities slightly reduced in diameter for the securing thereto of acupshaped base 3 to which the contact pins 4 and 4 are anchored.Envelope 2 has a re-entrant stem portion which is flattened at its innerend into a press 5 through which pass the filament mounting and lead-inwires 6 and 6. A filament 7, which may be the usual tungsten wire coilcoated with activated electron-emitting materials, is mountedtransversely across the ends of the wires 6, 6 within the envelope 2.

The end cap or base 3 is usually formed of some thin metal such as brassor aluminum; and, accordingly, it is necessary to provide some means forinsulating the pins 4 from the base. This is achieved by mounting thepins through oversize holes in the base and providing insulating washerson both sides of the hole for locating the pin. Pin 4 is provided withan annular flange or ridge 8 which seats against the outer insulatingwasher 9 and has a corresponding flange seating against another similarwasher on the inner side of the base 3. Thus, the pin is firmly anchoredand, at the same time, insulated from the metal of the base 3. Theexternal portions of the lead wire 6, 6 are pulled through the bore ofthe pins and are normally cut off flush with their ends.

In the usual manufacturing operations, it is necessary to pull up thelead wires through the pins in order to obviate any possibility ofmutual contact of the lead wires 6 and 6 under the base. In practice,the lead wires are pulled up sharply so that they are taut and noslackness is left in the wires between the seals in the press 5 and thecontact pins 4. As a result, it is necessary to insure that nostretching of the lead wires away from the seals occurs during thecrimping since, otherwise,

either the seal through the press or the lead-in wire will i be broken.

Referring to Fig. 2, there is shown in simplified pictorial outline apreferred apparatus for crimping the contact pin 4 and lead wire 6 andachieving the assembly described in the above-mentioned copendingapplication. The apparatus comprises a pair of relatively movablecompression dies 10 and 11 having corresponding semicylindrical grooves12 and 13 cut into their adjacent or contacting faces. When the dies 10and 11 are brought together, these grooves form a cylindrical cavitywherein the pin 4 is confined and which prevents any distortion of thepin during the subsequent indenting or crimping operation. Slots 14 and15 are cut into dies 10 and 11, respectively, in a plane normal to theircontacting faces, and located to abut on the semicylindrical grooves 12and 13, respectively. Slots 14 and 15 form channels through thecompression dies for allowing the inward movement of a pair ofpunches-16 and 17 against the pin 4, thereby to crimp it and achieve therequired indentation on opposite sides thereof.

The indenting faces of the dies 16 and 17 are shaped the sloping" faceson the" indenting punches is to initially grip-the lead wire Gin'thepin-4m the bottorn'or outer end of the pin. Thereaften the lead wiremetal flows upward through the bore of the pin as the crimpingoperationprogresses; and the' lead Wire is thus stretched-backtowardstheseal." This insures that the-portion of the lead wirebetweenth'e pin and the seal is lengthened rather than shortened and thusobviates any tendency towards either breaking ofthe wire-or the seal ofthe glass envelope of the lamp. I

In additionto the features whichhasbeendescribed whereby the frontfaceof the punch of the indenting punch slopes away: frorn theaxisof thepin, one of the punches, namely 16in the drawing; is slotted-near. itscenter so that,- in-fa'ct, the face of-the punch has twowedge-shapedp'ortions spaced slightly apart. This configurationcauses'apocketing-of the material of the pin between the twoindentations during the crimping operation. The metal of-the lead wirethereupon lumps under the pocket andinsures positivelocking. of the leadwire in the pin. This prevents any longitudinal sliding of the lead wirein-the' pin" even though it should subsequently split along theseam. Thecharacter and advantages of the resultin'gpin" configuration are morefully explained in the above-mentioned copeiiding application.

Referring to Fig. 3, th'ere-isshown a' machine into which thebasic-cornbinationof the compression'dies and indenting punches shown inFig. 2- is' incorporated for power actuation'thereof andautomaticcrimping of contact pins. ported on a bed plate or base 20, which'isformed into split bearing blocks 21 and 22 at either end. The leftcompression die is securely anchored to the bed plate with its frontface coinciding with a transverse plane through the center'of the bedplate. pression diel l is mounted withits front face facing the die 10and is adapted to slide on twodowel pins 23 and 24 which are'clampedincompression die 10. The indenting-punches'16 and17" and, likewise, thecorresponding pair 16 and 17" are mountedoirsteel blocks 18 and 19,respectively. These steelblocks are likewise adapted to slide'on the bedplate 20and are maintained in alignment-by' the-dowel-pins" 23 and 241It will be understood that the dowel pins project the required distanceson both'sidesof compression die' 10 to guide blocks 11 and 19 on theright-hand side and block 18 on the lefthand side for thefull l'ength oftheir path of movement.

The-rearward sides alongwith the top faces of compression dies 10 and 11are machined out into suitably shaped channels'or slots'for allowing themovement of the rectangular body' portionsof tli'e'ptinches 16-16 and17-17, respectively. The front faces of theblocks or compression'dies 10and 11 contain a pair of semicylindrical grooves 12-1-2- and 13-I3'which, upon movement ofthe blocks 10 and ll into: apposition, constitutethe cylindrical cavitiesfor confiriin'g'the pins 4-4 of the fluorescentlamp 1. A broken lower section of lamp 1 is shown in the drawing in aposition immediately above that which it occupies during the crimpingoperation of the=machine. It will be understood that for the actualcrimping operation; the lamp is lowered vertically so that the pins 4-4fit into the grooves 12-13 and 12-13, respectively.

The remainder of the machine is concerned with effecting the poweractuation of the compression dies and indenting punches and withautomatic control thereof. The necessary sequence of operations forcrimping the pins of the lamp-comprises, firstly; moving the compressiondie ll against thestationary compression die 10 in order to form thesemicylindrical cavities which grip the pins 4-4 and prevent anydistortion thereof; secondly, moving the punch blocks 18' and 19 forwardagainst the compression dies in order to allow the punches 12-12 and13-13 to indent thepins on'opposite sides thereof; thirdly, withdrawingthe indenting punches; and fourthly; withdrawing the movable compressiondie 11 in order to release the pins and permit withdrawal of the lamp.It will be understood'that many modifications may be made in themechanism for performing these four operations in the proper sequence.That which will now be described utilizes a single pneumatic aircylinder with suitable linkages for effecting all four operations andconstitutes a preferred embodiment of our invention.

The pneumatic air cylinder which provides the force necessary foractuating the mechanism is shown at 30,

The moving parts of the machine are sup The right com- 1thereofhas'beenbroken away inthe drawing. A' piston 31 mounted on a rod32 is adapted to move vertically up and down in the cylinder 30, themovement being controlled by the admission of compressed air eitherabove the piston through the inlet pipe 33 or below the piston through asimilar inlet pipe 34. The rod 32 of the air cylinder carries a yoke orcrosshead 35 which supports a pair of pins 36-and 37 mountedtransversely thereon.

The elements associated with pin 36, which are shown in'a so-calledexploded view to" the front of the machine, cause the actuation ormovement of the compression die 11 against the stationary'compressiondie 10. 7 It will be understood that these elements are duplicated onthe rearward side of the machine in'order to apply a balanced force tothe movable die 11. The transverse pin 36 carries a roller 38 at its endwhich rides in a slot or cam track 39 cut into alever 40. This lever ispivoted on a pin 41 fixed tothe bed plate 20 and engagesat its upper endin a cam=track 42a roller 43, which is mounted on a pin 44; Pin 44-,inturn, is fixed-to the" movable compression die 11 for forcing iteither towards" or away from the stationary compression'die 10.

The air cylinder starts'its active stroke from itsupp'ermost position,and the'ro'ller 38 riding in the eamtr'ack' 39 immediately causes amovement of the lower portion This causes lever to pivot of lever 40 tothe right; about pin- 41- in the sense shown bythearrow/'45 and;

in turn, causes movable compression die 11 to advance to the left andpressv firmly against-the forwardface-of stationary compression die 10.The movement of com pression die- 11 continues whileroller 38is inthe'upper inclined portionof the'cam track'39. As soon as roller 38 hasentered the straight verticalportion of the cam track, the movement ofcompression die 11 ceases,- and' it is simply held in fi xedcontact-with compression die 10. The straight vertieal-portionof' theslot 39 may thus' be considered asa lostmotion arrangement fortaking'careof the excess movement of air piston 31 which is news saryfor effectingthe operation of the indenting punches' necting links 53and 54 which provide the necessary cow pling for causing the movement ofblocks 18 and1'9 carrying the indenting punches 16 and 17',respectively; At the point in theair cylinder travel where the'roller 38enters the straight portion of the cam track 39 and the movement of thecompression die 11 ceases, thepin 37 engages the upper faces of the lostmotion slots 46; 46 and begins to'carry the'toggle links-49-an'd50"down=' ward. The slots 47 and 48 in the toggle links permit I thismovement, and the toggle links thus pivot about the pins 51 and 52- withrespect to the bed plate 20 The pivoting of the toggle links 49 and 50causes corresponding movements of the connecting links 53 and 54 whichcause blocks 18- and 19to' slide towards the compression die blocks onthedowel pins 23 and 24. The

punches 16-16 and 17-17' operating in the slots in thedieblocks'thereupon indent the pins of the lamp to make a permanent jointwith the lead wiresin the man ner previously described and more fullyexplained and illustrated in the copending application No. 180,818 ofRobert A. Kuebler.

As soon as the aircylinder has reached the bottom of its stroke, thesupply of compressed air is removed from inlet pipe 33 and is connectedto inlet pipe'34 in order to return the piston 31 to its uppermostpositionand to operate theindenting punches and compression dies inreverse order to that whichhas just been described. The supply of air tothe air cylinder may he controlled by the operator. However, we havefound it highly advantageous to rnechanize the whole operation so thatimmediately lamp 1 is inserted in the" slots This automatic operation isbrought about by Referring to Fig. 4, the crimping machine is shown in asomewhat simplified sectional view with certain parts removed in orderto facilitate showing the control system for achieving automaticoperation. The machine, as shown, has a lamp I mounted in the crimpingposition; and the electrical system is energized for actuating the aircylinder. In order to facilitate locating the pins 4-4 of the lamp 1 inthe semicylindrical grooves in the compression dies and 11, a guidemember or collar 60 is located immediately above these grooves and has asuitably shaped bottom plate 61 for guiding the pins.

When the lamp is properly positioned, the lamp pins 4-4 bear against apair of receiving pins 62 -62 which are mounted on a plunger 63 locatedimmediately below the cylindrical cavities formed when the compressiondies 10 and 11 are forced together. The receiving pins may be shaped toforce the lead wires a short distance back into the pins in order tocover up any sharp ends. Plunger 63 is normally pushed up to the top ofthe cavity 64 by means of a bell crank 65 which is hinged at 66 andbiased by means of a spring 67. The bell crank 65 actuates a suitableswitch 68 whenever the lamp is positioned within the collar or guide 60.

The machine is controlled by means of the switch 68 mentioned above anda second switch 69 which is actuated between one of two positions bymeans of pro jecting arms 70 and 71 on the yoke 35. These switches arepreferably of the type commonly known as microswitches having thegeneral appearance shown at 69 in Fig. 3. Switch 68 is normally open andcloses when actuated; switch 69 closes on the side to which it isactuated and remains so until further actuation. The electrical circuitis energized from a suitable voltage source connected across theterminals 7273 and comprises, in addition to switches 68 and 69, a relay74 and an electromechanical air valve 75. Relay 74 comprises anoperating coil 76, a pair of normally closed contacts 77 and a pair ofnormally open contacts 78. Air valve 75 comprises an operating coil 79,a normally closed air inlet valve 80 and a normally open air exhaustvalve 81 associated with supply tube 33, and a normally open air inletvalve 82 and a normally closed air exhaust valve 83 associated withinlet tube 34. The circuit connections may more readily be understood byreferring to the manner of operation of the apparatus, which form ofpresentation will henceforth be followed.

The machine, along with the associated control apparatus, is shown inthe position occupied immediately upon the insertion of a lamp withinthe guide 60 but before the relay 74 and the air valve 75 have had timeto operate. When switch 68 is closed by the depression of plunger 63, acircuit is completed through switch 68, the upper contact of switch 69,the normally closed contact 77 of relay 74, and the operating coil 79 ofair valve 75. The air valve is thus energized and its armature movesupwards, thereby opening valve 80 and closing valve 82, the associatedexhaust valves 81 and 83 being respectively closed and open. Compressedair is thus admitted to the top side of piston 31 within the cylinder30, and forces the piston 31 downward. The movements of the compressiondies 18 and 19 and of the indenting punches 16 and 17 thereupon occur inthe manner which has been described earlier.

At the bottom of the stroke of piston 31, the stop pin 70 and the yokeactuates switch 69 and opens the upper contact while closing the circuitthrough the lower contact. As a result, relay 74 is energized while theair valve 75 is simultaneously de-energized. The energization of relay74 breaks the circuit to operating coil 79 of the air valve through theupper contact 77 and prevents this circuit from being completed as longas the relay remains energized. The lower contact 78 of the relay at thesame time completes an auxiliary holding circuit which may be tracedfrom terminal 72 through switch 68, contact 78, operating coil 76, andback to terminal 73. This auxiliary holding circuit will maintain switch74 energized as long as switch 68 remains closed. The air valve 75having been de-energized, the compressed air supply is now connected tothe lower side of piston 31 in air cylinder 30, and yoke 35 is carriedupward, back to the rest position. The indenting punches 16 and 17 andthe compression dies 18 and 19 are thus retracted, and lamp 1 may beremoved from the socket 60. However, as long as lamp 1 remains in thesocket with the plunger 63 depressed, switch on another lamp whenever itmay be inserted in the,

socket 60.

It will be understood that a certain number of elements have beenomitted from. the description of the machine of Figs. 3 and 4 in orderto simplify the explanation and facilitate an understanding of itsmanner of operation. Thus, it will readily be realized that, inpractice, suitable bearings are provided for the different pins androllers and also that means are provided to permit fine adjustments ofthe different operating levers in order to obtain exactly the rightpressure and movement on the indenting punches and on the confiningdies. These adjustments are necessitated by the fact that differentindenting pressures may be required, depending upon the metal whereofthe pins 4 are made. For instance, considerably less pressure isrequired to indent aluminum pins than is required to indent similar pinsmade of brass.

While a certain specific embodiment has been shown and described, itwill of course be understood that various modifications may be madewithout departing from the spirit of the invention. Thus, variousmodifications may be provided in the mechanism for energizing the diesand punches; and, likewise, even with the machine which has beendescribed, modifications of the control apparatus are also possible forproviding the same or different operating characteristics. The appendedclaims are therefore intended to cover any such modifications comingwithin the true scope of the invention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. A crimping machine for tubular contact pins having a wire internallythreaded therethrough, comprising a bed plate, a pair of compressiondies, one fixed and the other slidably mounted on said plate, grooves inthe adjacent faces of said dies defining a cavity for gripping said pinwhen said dies are forced together, slots in said dies parallel to theirdirection of movement and terminating in said grooves, punches adaptedto advance through said slots for indenting said pin on opposite sides,a crosshead reciprocable perpendicularly to said bed plate, a linkagecomprising a lever pivoted on said bed plate and engaging said slidabledie and a portion of said crosshead for actuation thereby, and togglelinkages between said punches and said crosshead, said linkagesincluding lost motion means allowing actuation of said dies for grippingsaid pin previous to actuation of said punches.

2. A crimping machine for tubular contact pins having a wire internallythreaded therethrough, comprising a bed plate, a pair of compressiondies, one fixed and the other slidably mounted on said plate, grooves inthe adjacent faces of said dies defining a cavity for gripping said pinwhen said dies are forced together, slots in said dies parallel to theirdirection of movement and terminating in said grooves, punches adaptedto advance through said slots for indenting said pin on opposite sides,a crosshead reciprocable perpendicularly to said bed plate, a linkagecomprising a lever pivoted on said bed plate and having one portionengaging said slidable die and another portion engaged by said crossheadand including lost motion means to achieve positive actuation of saidslidable die followed by holding thereof in its actuated position duringfirst and second parts, respectively, of the motion of said crosshead,and toggle linkages between said punches and said crosshead includinglost motion means to achieve holding of said punches in their unactuatedpositions followed by positive actuation thereof during first and secondparts, respectively, of the motion of said crosshead.

3. A crimping machine for tubular contact pins having a wire internallythreaded therethrough, comprising a bed plate, a pair of compressiondies, one fixed and the other slidably mounted on said plate, grooves inthe adjacent faces of said dies defining a cavity for gripping said pinwhen said dies are forced together, slots in said dies parallel to theirdirection of movement and terminating in said grooves, punches adaptedto advance through said slots for indenting said pinon.- opposite sides,a crosshe'ad reeiprocable perpendicularly to said bed plate, pneumaticmeans actuatingsaid crosshead, a linkage comprisingia lever. pivotedonsaidb'e'd plate and having-one'portion engaging said siidable die andan-- other portion engaged by said c'r'osshead and including lost motionmeans to achieve positive actnation of said slidable die followed byholding thereot in'it's actuated position during first and second parts,respectively, of the motion of said crosshead, andtoggle linkagesbetween said punches and said cro'ssliead includinglost motion means toachieve-holding ofsaid punches in their unactuated positions followed bypositive actuation there-- of during first and second parts,respectively, of the motion of said crosshead, a plunger located belowsaid dies and actuated upon insertion of a contact pin" into the spacebetween saiddies; a switch actuated by said plunger, and an electricallycont-rolled fluid valve for 8 said pneumatic means; said val've having acontrol coil in circuit with said switch.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,359,135 Wet mo're Nov. 16, 1920 2,262,802 Hayden Nov. 18,1941 2,289,108' Eaton July 7, 1942 2,379,305 Kaminky June 26, 19452,382,292 Carlson Aug. 14, 1945 2,438,999 Hartley etal; Apr. 6, 1948FOREIGN PATENTS Number Country Date 632,126 Germany July 3, 1936

